Automatic firing means for gyro stabilized guns



Feb. 5, 1946. A. R. STONE 2,394,021

AUTOMATIC FIRING MEANS FOR GYRO STABILIZED GUNS Filed Sept. 2, 1943 Alberc R. Sim-1e Patented Feb. 5, 1946 AUTOMATIC FIRING MEANS FOR GYRO STABILIZED GUNS Albert Rivington Stone, Anneslie, Md.

Application September 2, 1943, Serial No. 500,929

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 7 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to gyro-stabilizer mechanism for guns mounted in tanks and other vehicles. Gyro-stabilizing gun devices are designed to maintain the gun in its aimed position irrespective of the up-and-down movement of the tank due to ground irregularities. A gyrooperated mechanism within the stabilizer, whenever it is disturbed by the vertical movement of the tank, will cause the gun to be turned on its trunnion in a sense opposite to that of the tank movement. If the tank dips downwardly as it encounters a depression, the gyro stabilizer will cause the gun to be turned in the opposite, or upward, sense, thus returning the gun to its aimed position; as the tank swings upwardly in leaving the depression or in mounting a hill or obstacle, the gyro stabilizer causes the gun to be turned downwardly. The gyro stabilizer thus causes the gun to be oscillated on 'bothsides of the aimed position as the tank itself oscillates or swings up and down over the road contour.

When firing the gun as it is'thus oscillated by I the gyro stabilizer, the gunner presses the trigger when the target swings across the hair line of the sight. It is difficult to catch the target when it is precisely on the hair line, especially since there is some delay on the part of the senses in actually firing; moreover, there is also some delay in the operation of the firing solenoid and its linkage. The object of this invention is to provide means for firing the gun automatically, just as the cross hairs of the sight lie directly on the target. As a matter of fact, it may be desirable to fire the gun just before the cross hairs lie on the target, to compensate for the time required for the firing solenoid to operate. A further object of the invention is to devise automatic gun firing means of the character described which may be readily added to the existing gyro stabilizer system with the minimum of changes or alteration. For the attainment of these and such other objects of invention as may appear herein or be pointed out I have shown one embodiment in the single figure which constitutes the accompanying sheet of drawings.

Before describing the automatic gun firing means of this invention, the gyro stabilizer as now employed in controlling the aiming of guns mounted on tanks will first be explained. The essential part of the gyro stabilizer is a highspeed gyro, which is not shown but which controls the position of a member I which is interposed between a plurality of swinging contact blades 2 which constitute a set of left-hand contacts and resistors and an equal number of right-hand contacts and resistors 3. The circuit through the left and right contacts 2 and 3 originates at a common source of current 4 and divides into two branches, one going through left contacts 2 and the other branch going through right contacts 3. The left branch includes an electromagnetic coil I2 while the right branch includes electromagnetic coil I3. Left and right branch circuits coils I2 and I3 have a common juncture at ground connection 5. The division of current as between left branch circuit 2I2' and right branch circuit 3-I3 depends upon the position of the gyro contact spacer I. As shown in the drawing, the same numberfive--of contacts are made in both the left 2I2 and right 3-I3 circuits when the gyro-controlled spacer I is in its vertical or normal centralized position (as shown). Therefore, as long as spacer I remains centered, an equal amount of resistance in resistors 2 and 3 is shorted out, and an equal amount of current will be supplied to magnet coils I2 and I3. The magnet coils I2 and I3 control the position of a magnet bar III which is balanced at its midpoint (the magnet bar It controls oil pressure in a hydraulic system, subsequently described). With an equal amount of current in each magnet coil I2 and I3, the magnet bar remains balanced.

With the equipment in its balanced position (as shown in the drawing), suppose a displacement of the gyro control caused by motions of the tank causes the spacer I to move, say, to the left in the drawing This leftward movement of gyro spacer I causes more contacts to be made in the left circuit 2-I2 and all of the contacts in the right circuit 3I3 to be opened. Under this condition. most of the resistance of the left resistors 2 is shorted out and all of the resistance of right resistors 3 is in the circuit. This closing of left contacts 2 and opening of right contacts 3,

changing the effective resistance of the respec-' tive left and right resistors, increases the current along the left circuit 2--I2 to magnet coil I2 and decreases the current along the right circuit to magnet coil I3. As a result, magnet bar I 0 assumes an unbalanced position and thus effects a change in the hydraulic system (as will 1 now be described). A

The magnet coils I2 and I3 and their magnet bar I0 are contained within an oil-filled vessel 4| which also contains an oil pump 2| provided with two discharge pipes 22 and 23 both leading to an oil cylinder 20. The piston 24 of the oil cylinder is operatively connected to gun 6 which is mounted for elevational turning on its trunnion 1. One of the two said oil discharge pipes, 22, leads to a point above the piston 24 while the other discharge pipe 23 leads to a oint below the piston. Both discharge pipes 22 and 23 have short branch outlets, respectively, 22a and 23a, leading to orifices, respectively, 42 and 43, provided in a frame member 40. The outlet of the upper orifice 42 is controlled by a needle valve 32 at the upper end of magnet bar l0, while the outlet of lower orifice 43 is controlled by a needle valve 33 at the lower end of magnet bar H). The pump 2| circulates oil, from suction inlets at the pump, through the upper discharge pipe 22 and its outlet 42 and through the lower discharge pipe 23 and its outlet 43. The oil pressure above and below piston 24 is controlled by varying the resistance to the flow of oil through the orifices 42 and 43, such resistance depending upon the relative position of needle valves 32 and 33 which in turn depends upon the position of magnet bar It.

We had assumed above that the gyro spacer I had shifted to the left causing an increase in current to the upper magnet coil I2, in the left branch 2-i2. This increase in current in upper coil l2, accompanied by a decrease in current to lower magnet coil l3, causes a turning of the magnet bar III in a clockwise sense, as viewed in the drawing. This unbalancing turning of bar Iilforces needle valve 32 towards orifice 42 to decrease its outlet area and withdraws needle valve 33 from lower orifice 33 to increase its outlet. The restriction in the size of the upper orifice 42 results in an increase in oil pressure in the upper discharge pipe 22 while the further opening of the lower orifice 43 results in a lowering "of the oil pressure in the lower dis-.

charge pipe 23. Therefore, with the oil pressure increased in upper pipe 22 and decreased in lower pipe 23, the piston 24 will move downwardly, to pull the breech down and the muzzle up.

The foregoing description has been concerned with the'gyro stabilizer as used at present, with manual firing of the gun as it oscillates on both sides of the target. To implement the gyro stabilizer with the automatic firing means of this invention a balanced coil solenoid 8-9 is shunted across the left circuit 2-I2 and the right circuit 3-13 in such a manner that one coil 9 of its two coils is connected to the left branch 2l2 and the other coil 9, connected to the right branch 3-l3. The other end of solenoid coils 8 and 9 make a common juncture at ground connection .H. The armature l6 of the balanced coil solenoid 9-9 controls a normally open switch 15 which is in the firing circuit to the firing mechanism l4.

A balanced coil solenoid is one whose armature is actuated only when the current fiow through each of its pair of coils is precisely equal; under all other conditions of inequality in the two coil currents, the solenoid will not actuate its armature. As mentioned above, switch l5,' which preferably is of the micro-switch type, is normally open. Hence the balanced coil solenoid 8-9 will be ineffective to close switch 15 except only when there is an equality of current fiow in its paired coils. As pointed out in the description of the gyro-controlled stabilizer the current in the left branch 2--l2 and the right branch 3|3 will be equal only when the gyro-controlled spacer l is in its central position (as shown in the drawing). Since the two coils of the balanced coil solenoid 8-9 are connected across the left and right branches respectively, 2'-l2 and 3-43, of the gy o stabilizer circuit, there will be an equality of current in the coils 8-9 of the balanced coil solenoid only when the gyro spacer I is in its central position. Hence the firing circuit will be closed only at the instant that the gun is at aiming position, at the center of its oscillation. By selection, the circuit constants can be made so that the sensitive relay will open just enough in advance of the null point to compensate for the time delay of the firing relay and thus the gun can be made to fire at the moment it is on the target, regardless of the amplitude of oscillation.

In sighting, the gunner aims to cause the gun to oscillate above and below the target an approximately equal amount. When the firing switch I! is depressed the gun will automatically fire as the sight cross hairs center on the target.

I claim:

1. In a device for stabilizing a tank-mounted gun of the type provided with an oil cylinder having its piston articulated to the gun for elevational turning, an oil chamber having a partition provided with an upper and a lower orifice, a pump within the said oil chamber having its inlet opening therein and provided with an upper discharge pipe connected to the said oil cylinder above the piston and a lower discharge pipe connected to the oil cylinder below the piston, the said upper discharge pipe having a branch connection to the said 'upper orifice and the said lower discharge pipe having a branch connection to the said lower orifice, a magnet bar within the oil chamber pivotally mounted at its midpoint and provided with an upper needle valve associated with the said upper orifice and a lower needle valve associated with the said lower orifice, an upper electromagnetic coil associated with the upper arm of the magnet bar and a lower electromagnetic ,coil associated with the lower arm of the magnet bar, a gyro controlled member adapted to swing in response to the vertical pitching of the tank about a centered position corresponding to the aimed position of the gun, a plurality of contact-resistor elements disposed to the left of the said gyro controlled member and an equal number of contact-resistor elements disposed to the right thereof, and a two-branched circuit one branch of which includes the said left plurality of contact-resistor elements and the said upper electromagnetic coil and the other branch of which includes the said right plurality of contact-resistor elements and the said lower electromagnetic coil, adapted when the said gyro controlled member shifts to the left to cut out resistors in the said left contactor-upper coil branch and to cut in resistors in the said right contactor-lower coil branch to increase the current in the first branch and to decrease the cur-' rent in the second branch whereby the said mag- .net bar is tilted to cause the said upper needle valve to restrict the said upper orifice and to cause the said lower needle valve to open the said lower orifice whereby the pressure in the said upper discharge pipe is increased and the pressure in the said lower discharge pipe is decreased to cause the said piston to move downwardly and vice versa, the combination of, a balanced coil solenoid the two coils of which are grounded across respective ones of the two said branch circuits, the armature of which is actuated only when the current in both coils is equal, and a firing circuit including a normally opened switch closed upon actuation of the said solenoid armature when the current in both branch circuits is equal whereby the gun is fired when the said gyro controlled member swings across its said centered position corresponding to the said aimed position of the gun.

2. In a device for stabilizing a tank-mounted gun of the type provided with an oil cylinder having it piston articulated to the gun for elevationai turning, an upper and a lower, orifice, a,

pump provided with an upper discharge pipe connected to the said oil cylinder above the piston and a lower discharge pipe connected to the oil cylinder below the piston, the said upper discharge pipe having a branch connection to the said upper orifice and the said lower discharge pipe having a branch connection to the said lower orifice, a magnet bar pivotally mounted at its member adapted to swing in response to the vertical pitching oi the tank about a centered position corresponding to the aimed position of the gun,

3. In a device for stabilizing a tank-mounted gun of the type provided with a hydraulic cylinder having its piston articulated to the gun for elevational turning, and means for regulating the pressure of the said hydraulic cylinder including a gyro controlled member and a two branch electrical circuit the current distribution of which is governed by the said gyro controlled member, the combination of a balanced coil solenoid the two coils of which are grounded across respective ones of the two said branch circuits, the armature of which is actuated only when the current inboth coils is equal, and a firing circuit including a normally opened switch closed upon actuation of the said solenoid armature when the current in both branch circuits isequal whereby the gun is fired when the said gyro controlled controlled rnember, the combination of a balanced coil solenoid the two coils of which are grounded across respective ones of the two said branch circuits, the armature of which is actuated only when the current in both coils is equal,

- and, a firing circuit including a normally opened a plurality of contact-resistor elements disposed to the left of the said gyro controlled member and an equal number of contact-resistor elements disposed to the right thereof, and a two-branched circuit one branch of which includes the said le'ft plurality of contact-resistor elements and the said upper electromagnetic coil and the other branch which includes the said right plurality of contact-resistor elements and the said lower electro-magnetic coil, adapted when the said gyro controlled member shifts to the left to cut out resistors in the said left contactor-upper coil branch and to cut in resistors in the said right contactor-lower coil branch to increase the current in the first branch and to decrease the current in the second branch whereby the said magnet bar is tilted to cause the said upper needle valve to restrict the said upper orifice and to cause the said lower needle valve to open the said lower orifice whereby the pressure in the said upper discharge pipe is increased and the pressure in the said lower discharge pipe is decreased to cause the said piston to move downwardly and vice-verse, the combination of a balanced coil solenoid the two coils Of which are grounded across respective ones of the two said branch circuits, the armature of which is actuated only when the current in both coils is equal, and a firing circuit including a normally opened switch closed upon actuation of the said solenoid armaotthegun.

switch closed upon actuation of the said solenoid armature when the current in. both branch circuits is equal whereby the gun is fired when the said gyro controlled member swings across its centered position corresponding to the aimed position of the gun.

5. In combination with a gyro controlled sta bilizer for a gun, a firing circuit, a yro con trolled member, a two branch electrical circuit, variable resistance members in said circuit varied by movement of said gyro controlled member,

and means in said circuit constructed and arranged to energize said firing circuit when said gyro controlled member moves across a predetermined point in its movement,

6. A device as set forth in claim 5 wherein each branch of said electricalcircuit is connected to independent coils in a balanced coil solenoid, an armature in said solenoid, and a switch in said firing circuit energized upon movement of said armature.

'7. In combination with a gyro controlled stabilizer for a gun, a gyro controlled member, a firing circuit, a two-branch electrical circuit, variable resistance members in each of said circuits, varied by movement of said gyro-controlled member, an energizable member to which each of said branches is connected, means for cooperating with said member constructed and arranged to energize said firing circuit, said member being energized only when said gyro controlled members are in a predetermined position.

ALBERT RIVmGTON STONE. 

